Morphological, mechanical and AC electrical conductivity of polyvinyl alcohol loaded with single walled carbon nanotubes

Two series of polyvinyl alcohol/single walled carbon nanotubes (PVA/SWCNTs) nanocomposite films were prepared using sonicator in double distilled water solution to obtain a well dispersion of SWCNTs in polyvinyl alcohol as a host material using casting techniques. The mechanical properties are significantly improved and enhanced as compared to the pure PVA film after adding the SWCNTs. Young's modulus and tensile strength are increased after adding SWCNTs. The prepared films are studied by TEM and AC conductivity measurements. The TEM demonstrated that SWCNTs is well distributed in PVA matrices with some broken of SWCNTs revealing that SWCNTs broke aside as opposed to being pulled out from fracture surface suggest an interfacial bonding with some wrapped around PVA. The maximum values of AC conductivity are observed at the higher frequency. Both dielectric constant (ε') and dielectric loss (ε") are decreased with an increase of the frequency related to the direction of dipoles in PVA matrices orient toward applied field. Decrease trend at maximum frequency has seemed stable due to difficult of dipoles rotation. The values of dielectric parameters are increased gradually with the increase in both the temperature and the concentration of SWCNTs.